President Barack Obama is facing mounting pressure to produce proof the Russians were behind the cyberattacks in the presidential election, The Hill reports.

Despite its assessment that the Russians tried to interfere during the campaign, the administration has produced little evidence so far to back up its claims.

And it has not released any evidence to confirm claims from anonymous officials that the CIA is convinced Russian President Vladimir Putin coordinated the hacking to ensure President-elect Donald Trump's victory, according to the Hill.

Obama has ordered a detailed review of the hacking before Trump's Jan. 20 inauguration. But the Hill says the report will include "highly sensitive and classified information" — making it uncertain how much evidence will be released to the public.

Trump and his team have dismissed the claims of Russian involvement and treated them as an attack on the legitimacy of his election.

"If the CIA Director (John) Brennan and others at the top are serious about turning over evidence … they should do that," Trump aide Kellyanne Conway said. "They should not be leaking to the media. If there's evidence, let's see it."

But Obama maintains, "There are still a whole range of assessments taking place among the (intelligence) agencies. But that does not in any way, I think, detract from the basic point that everyone during the election perceived accurately — that in fact what the Russian hack had done was create more problems for the Clinton campaign than it had for the Trump campaign."

Meanwhile, ABC News reports Obama could release some details of the Russian hacking as early as Thursday.

The network news said the administration is getting set to announce retaliatory steps against Russia for the cyberattack.